There are many environments where it is necessary to duplicate confidential documents. For example, patient files may need to be duplicated from one doctor to another doctor. In addition, in an office environment there are often documents relating to new projects, new products, etc., which may well be confidential to the company.
Without adequate security measures it is very easy for a confidential document of this type to be sent to people who should not be receiving the information contained therein. This is often done by people copying the confidential document and then putting it in an envelope and sending it as mail. The mail is not always opened by the person for whom it was intended, sometimes being opened by a secretary or other member of staff. This means that very often confidential documents are read or fall into the hands of people who should not see them or should not have them.
In addition, the document may be copied many times and the person who owns the document may not know how many copies are in circulation. It would obviously be better for the owner of the document to have an indication of how many documents are in circulation in order to control and retrieve the document should the need arise.
A certain number of proposals exist on the subject of copying and securing confidential documents. In several of these proposals, the suggestions of including a tag with the document are described. In one the tag serves to enable or disable a copier from authorizing or not the printing of a copy. This can be overcome by removing the tag or just using a different copier. This system is not generally sufficient to overcome the known problems in this field.
In another example the tags allow the identification of a relevant tray in a copier to be used. The tray includes a pre-tagged sheets of paper which enable a tagged and confidential document to be copied onto another tagged and confidential document.
A disadvantage of the second example is that the pre-tagged pages do not have any indication of the type of document that is being copied and do not include any information relating particularly to that document. All tagged documents are therefore the same, merely indicating that the document is confidential and nothing more. There is no way of knowing (without looking at the copied documents) which documents have been copied and how many times.